The present invention relates to a method of producing vinyl chloride polymer or copolymer through the suspension polymerization process. In particular, it relates to a production method of vinyl chloride polymer or copolymer having excellent fluidity.
The vinyl chloride polymer or copolymer is usually produced through the suspension polymerization process and, after the refinements such as separation from slurry and drying, it is conveyed by the pneumatic transportation for storage or bag-filling.
However, the vinyl chloride polymer or copolymer thus obtained carries the static electricity through the frictions by itself and with other materials in the processes of conveyance and bag-filling to reduce the fluidity and to decrease the bulk density over the vinyl chloride polymer or copolymer just after the production. Hence, it becomes remarkably difficult in handling, posing a problem of serious obstacles in operation. As the methods of alleviating the adverse effect due to such electrification of polymer, a method to add a nonionic surfactant, cationic surfactant or the like being an antistatic agent to vinyl chloride polymer or copolymer and a method to adjust the humidity by blowing the steam into vinyl chloride polymer or copolymer have been employed so far.
Said method to add the surfactant, however, has such drawbacks that it cannot enough prevent the decrease in bulk specific gravity of polymer and, in addition, it adversely affects the thermal stability and the initial coloring property of product. Moreover, the method to blow the steam has drawbacks of increased labor requirement, complicated equipment and the like.